K-Band GaN Based Solid State Power Amplifier for Space Applications

This paper details the design and realization of State-of-the-art, K-Band Solid State Power Amplifier (SSPA) for Space Applications. This Monolithic Microwave Integrated Circuit (MMIC) based SSPA is developed indigenously utilizing in-house designed GaAs and GaN amplifier MMICs in driver and high power stages. The SSPA delivers >5W Continuous Wave (CW) output power at 4dB gain compression with large signal gain better than 64dB at the center frequency of 26.07GHz over a bandwidth of 100MHz. The design verification model (DVM) is developed and tested successfully over a temperature range of −5°C to +60°C meeting all the required specifications. The overall high gain of SSPA is split in two separate mechanical housings namely Driver Amplifier (DA) package and High Power Amplifier (HPA) package, which are interconnected using a small co-axial cable. Separate Electronic Power Conditioner (EPC) package provides regulated DC power required by the SSPA. Design challenges pertaining to high frequency-high power design and thermal management aspects for space environments are also discussed in the paper.